What is unique about Python?

[gsteff]

I'm a computer science student, and have recently been trying to
convince the professor who teaches the programming language design
course to consider mentioning scripting languages in the future.  Along
those lines, I've been trying to think of features of Python, and
scripting languages in general, that can't be found in older languages,
and have been having a surprising amount of trouble.  Dynamic typing
can be found in Smalltalk, the module concept can be found in Ada,
functional parameters and the dynamic creation of functions can be
found in Lisp.  The indentation-based syntax seems to be unique, but
that's not really what I'm looking for.  So I'm wondering, what is
innovative about Python, either in its design or implementation?  Or is
its magic really just in combining many useful features of prior
languages in an unusually pleasant way?

Greg